sitter
noun
[ ˈsɪtə ]
• a person who sits, especially for a portrait or examination.
• "she always hopes to imbue a portrait with the sitter's character"
• a person who looks after children, pets, or a house while the parents or owners are away.
• "a house-sitter"
• (in sport) an easy catch or shot.
• "he scored some great goals but missed some sitters"